Calling a method with getattr in Python
- by brain_damage
How to call a method using getattr?
I want to create a metaclass, which can call non-existing methods of some other class that start with the word 'oposite_'. The method should have the same number of arguments, but to return the opposite result.
def oposite(func):
return lambda s, *args, **kw: not oposite(s, *args, **kw)
class Negate(type):
def __getattr__(self, name):
if name.startswith('oposite_'):
return oposite(self.__getattr__(name[8:]))
def __init__(self,*args,**kwargs):
self.__getattr__ = Negate.__getattr__
class P(metaclass=Negate):
def yep(self):
return True
But the problem is that
self.__getattr__(sth)
returns a NoneType object.
>>> p = P()
>>> p.oposite_yep()
Traceback (most recent call last):
File "<pyshell#115>", line 1, in <module>
p.oposite_yep()
TypeError: <lambda>() takes at least 1 positional argument (0 given)
How to deal with this?
